What They Say
Analyst IDTechEx has put out a report on headset optics highlighting birdbath, holographic and dynamic focus optics as being likely to replace Fresnel lenses in XR headsets over the next decade. Fresnel lenses are relatively simple and cheap but have significant optical disadvantages.
IDTechEx says that the first wave of these newer designs focuses on compactness, using technologies such as so-called “pancake” lenses – short, wide components already used in photography.
“Polarization-based pancake lenses saw their first entry into Western headset markets in 2021 with HTC’s Vive Flow, with further releases from Shiftall/Panasonic and possibly Meta expected in 2022.” reports the analyst firm.
However, pancake optics can have low efficiency although IDTechEx points out that later iterations are expected to solve the vergence-accommodation conflict, thus maximizing immersion while eliminating the effect that can cause VR headset wearers to suffer from motion sickness. (See the DD from last week for a good slide on the issue of V/A conflict Innolux Shines a Light on Kirameki and Natural3D )
Another example of a compact optical design is catadioptric freeform prism lenses, which IDTechEx also tips to make an impact this year.
“Surface relief diffractive waveguides, as used in Hololens and Magic Leap devices, have made early strides,” says the firm. “Manufactured via processes inherited from the silicon industry, these enable relatively slim and compact devices but suffer from high costs, image quality issues and poor efficiency.”
Alternatives include holographic diffractive waveguides and reflective waveguides, which IDTechEx says promise to “revolutionize” manufacturability and “redefine” image quality respectively – although these are yet to gain significant market traction.
The article goes on to discuss the issues of etendue in optics for AR and the impact on FOV and eyebox limits.
One long-term prospect for XR devices could be dynamically focus-tunable geometric phase lens arrays, using holography or metasurfaces. Although these are still years from deployment currently, IDTechEx has noted interest and patent activity from the likes of Meta, Valve, and Apple.
“This once-static field has transformed into a hotbed for innovation,” states the report, adding that the market for XR optics will grow at a compound average rate of 24 per cent over the next decade – thus ending up nearly an order of magnitude larger.
What We Think
It’s amazing how much work is going on in this area, but a potential for 24% CAGR is bound to attract interest. (BR)
